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NSTRUCTIONS 



,ve FROM THE 



PLAIN INSTRUCTIO 






TO PREPARE AND PRESERVE FROM THB 

RUST, 
WROUGHT AND CAST IRON & STEEL, 

LIKEWISE THE METHOD TO COVER 

IRON WITH A SURFACE OF COPPER, 

LIKEWISE THE METHOD TO MAKE AND PREPARE 

THE GALVANIC POWDER AND PAINT, 

/ 

Br GEORGE JOHNSON, 

FORMERLY FREE MERCHANT OF CALCCTTA. 



NEW YORK: 

PKINTED AND PUBLISHED FOR THE PROPRIETOR 

BY W. B. & T. SMITH, 

89 Nassau, and 123 Fulton-sts. 

1842. 



issi ^yi^K^h^ ^ii^iB^a^ssessxss^sassmiie^z^siec^i 



^EEL, 

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ERRATA. 

Page 19, lino 5, read if the Troughs &c. 
do do line 7, read, that are not lined, 
do do line 30, read, tun if it is employed, $e. 



PLAIN INSTRUCTIONS 



TO PREPARE AND PRESERVE FROM THE 



RUST, 



Wrought & cast iron & steel, 



LIKEWISE THE METHOD TO COVER 



IRON WITH A SURFACE OF COPPER, 



&' 



LIKEWISE THE METHOD TO MAKE AND PREPARE 



THE GALVANIC POWDER AND PAINT, 



/ 



By GEORGE JOHNSON, 

FORMERLY FREE MERCHANT OF CALCUTTA. 



NEW YORK: 
PRINTED AND PUBLISHED FOR THE PROPRIETOR BY W. B. & T. SMITH, 
i ^\ 89 Nassau Street, and 128 Fulton Street. 



\ \ PHI 



r- 



1842. 






Entered according lo Act of Congress in the year of our Lord, 1S42, by ' 
GEORGE JOHNSON, 
in the Clerk's Office of the Southern District of New York. s 



sr 






PREFACE 



To my friends the public, before the great 
public, I present myself with homage and re- 
spect; and my object for so doing, is to give 
them information upon a subject which is of 
immense importance to their interests. 

To say, that I am going to discourse upon the 
preservation from Rust, of Iron, Cast Iron and 
Steel, is to say a great deal; to say Iron, Cast 
Iron and Steel can at a very small expense be 
rendered Rust proof, is to speak volumes to 
every practical and reflecting mind ; yet such is 
the fact, and I am going to prove it. After more 
than four years experience and observation in 
this business in Paris, France, I will relate my 
views in a plain, unvarnished manner. First, 
then, I think nearly every article of Iron, Cast Iron 
and Steel ought to be galvanised ; and for the 
simple reason that it costs so little to do it, and 
yet when well done it is done for ever; one cent 
per pound is all they charge in Paris for gal- 
vanising articles brought to them, when these 
articles are of any considerable weight, such for 
example as pipes for stoves, water pails, locks, 
spring wire for seats, &c. But before I proceed 
any further I will state the reason why it costs 
so little to galvanise, otherwise to zinc Iron, &c. 
I claim the merit and honor of being the first 
individual that ever promulgated in this country 
the knowledge, that sulphuric acid, that has been 
made use of for refining oils, is the article they 
Use in Paris since about three years, to cleanse 
the oxyde of the metals, and that it actually an- 
swers better than sulphuric acid that costs so 
much money ; it is after the oil refiner has done 
with it for his use, so that he is glad to be rid of 
it for nothing; this is precisely the article that 
does so well to cleanse the oxyde of the metals, 
thereby replacing an article that costs a great 
deal, by another which costs simply the carriage 
of bringing it to the manufactory where it is 
wanted : this is the first important economy in 
galvanising Iron t the second is that instead 
of using sal-ammoniac, which is a very expen- 
sive article in the items of galvanising, on ac- 
count of the very great quantity necessary to be 
employed j they use in Paris since about three 



yejafs the coarsest kind of muriatic salt oiherwip© 
called muriate d' ammoniaque or sel non sub* 
lime", which does not cost but about half the for* 
mer in the firbt instance, and lasts much longer 
being a stronger bodied article ; the economy 
effected upon these two important articles, re- 
duces the price of galvanising aa before stated 
to one cent per pound. 

Rosin, lamp oil and other substances have 
been tried in Paris to endeavor to economise 
upon this muriate d' ammoniaque or sel non 
sublime, but nothing as yet has been discovered 
to succeed so well ; it is absolutely necessary 
whilst galvanising for the zinc to be well and 
entirely covered with this salt, to prevent it from 
oxydising. 

To such an extent is this idea of galvanising 
or zincing every article carried in Paris; that 
they even galvanise a course kind of wire 
work or wire cloth, which is there employed in 
the place of laths for partition walls: the plaster 
will adhere readily to it, and besides the advan- 
tage of not being scarcely any more expense 
than laths in the first instance ; it will endure 
fifty times as long; takes up less room; and 
will not burn as laths do in the unfortunate 
event of a fire ; the finer kinds of wire cloth 
adapted for sieves in the place of horse hair 
cloth, answers admirably, is a hundred times 
more economical than horse hair cloth for this 
purpose, and the first cost is very little more; 
this article is likewise galvanised to a great ex* 
tent at Paris. 

I will notice in this place, that the article 
which will probably be considered of the most 
importance ; is Sheet Iron destined either for 
sheathing of vessels in the place of copper ; or 
for roofing of every kind ; for sheathing of ships, 
the first cost will not probably be more than a 
third ; and will endure longer than copper, 
being harder than it: for roofing it is equally 
important, and equally economical ; and this 
naturally leads me to describe the best method 
of preparing these sheets of Iron, so that they 
may not be rendered brittle and unfit for use : 
after cleansing the oxyde of the surface of tbe 



5 



PREFACE 



sheets of Iron by means of the acids diluted 
with water : See Instructions : we arrive at the 
extremely important point of dipping the sheets 
of Iron in the melted zinc : the true art of gal- 
vanising these sheets of Iron, being thoroughly 
cleansed previously from the oxyde: is to have 
the zinc bath as hot as possible, and well covered 
with the muriatic salt; and as the salt consumes 
as much more rapidly, as the zinc is more in- 
tensely heated ; it is necessary to have a pailfull 
of the salt close at hand ; so that the workman 
may be able to throw on the surface of the zinc 
fresh salt as often as he perceives it is required, 
let there be no stint of muriatic salt if you wish 
to do the articles well; the workman dips the 
sheet of Iron, which he holds by the pincers A. 
See Engraving : into the zinc bath, quick, 
briskly ; leaves it in for a quarter of a minute or 
so, balances the sheet in the prongs of the pin- 
cers, which he moves to prevent any trace of the 
pincers being left on the sheet of Iron, then 
draws out the sheet slowly, and hands it over to 
another workman who is placed on the opposite 
side of the bath to him; this second workman 
will take the sheet of Iron after being very par- 
ticular to dip the edge of the sheet into the flux 
or muriatic salt which must always well cover 
the zinc, he will carry it, and stand it on its edge 
on a wooden frame made on purpose to contain 
them: here, my worthy readers will please to 
remark, the sheet of Iron has not yet touched 
the water, either warm or cold ; and I particular- 
ly recommend to all those who wish to have 
good malleable sheets of Iron not to be too hasty 
in plunging the sheets into water, it is better for 
the toughness and malleability of the Iron to 
leave it to become cooler (say about from 5 to 
19 minutes) than it is when it quits the zinc 
bath, before attempting to wash off the blackish 
stains caused by the muriatic salt: this is the 
method now adopted at Paris, and found to 
answer perfectly well; for if a man understands 
his business, the metals so far from being render- 
ed brittle in galvanising them, are in reality, 
more tough and malleable: for a great length of 
time this same method of plunging nails into 
water immediately they came out of the zinc 
was adopted; but now it is found much better 
instead of scattering them into a tub of water, to 
scatter them upon the ground, and when they 
hare become cool to put them into a barrel turn- 
ing on an axletree with some water and coarse 
sand to wash them clean: it takes about 15 
caiuutes to cleanse them. 



It is necessary to skim the muriatic salt of the 
zinc, each time the workmen go to their meals 
to economise it; and to skim the oxyde of the 
zinc before again commencing, and previously 
to again putting the muriatic salt on the bath : 
these skimmings and the dross deposited at the 
bottom of the zinc bath, serve to make the 
galvanic paint powder : it is well each time the 
workman adds fresh muriatic salt to mix it, by 
stirring it up with the old. 

All articles such as wire work, and to which 
muriatic salt will adhere when they draw 



the 

them out of the zinc ; it would be well to gently 
beat these articles with an iron rod to knock off 
the excess of muriatic salt into the bath, which 
otherwise would be wasted, when the articles 
are plunged into the water. 

Unless the articles are quite hot it is necessary 
to immerse them in the zinc bath quite slowly to 
prevent an explosion, and to draw them out 
again very slowly to prevent the zinc from form- 
ing into lumps at the ends; then again if they are 
small articles to give them a brisk shake, i.e. let 
the arm fall quick, and bring it back in turning 
up the arm to prevent the zinc from filling up 
the teeth of any article such as a curry comb. 

In drawing out the curry combs, it is necessary 
to draw them out but a little, before laying hold 
of them with the pincers C. See Engraving: 
incline the objecta little, so that the zinc may run 
down the object, instead of leaving a lump or bit 
at the end. 

It is very important to bear in mind, that all 
articles, with which it is practical should be turn- 
ed immediately they are taken out of the bath 
of zinc, to prevent the zinc from forming into 
lumps at the end of the article. 

It is better as often as you have occasion to 
draw an article out of the zinc, to push up the 
muriatic salt to the edge of the article. 

See Engraving : letter E. for form of the iron 
rod made use of for dipping the iron wire ; the 
wire is made to turn on this rod in immersing it 
in the zinc, and also when it is drawn out of the 
Bath, and likewise in the Tub of water : For 
another form See Engraving : letter D. This 
form is made use off when you have Wire-work 
worked into sheets to be galvanised it is simply 
necessary to pass one end of the Handle through 
any part of the Wire-work that is most conve- 
nient, and to slip it along the handle until it arrives 
in the circle ; these rods are formed out of 
wrought Iron, one quarter of an inch in diameter, 
and about four feet in length 



PREFACE 



In galvanising Nails ; the iron basket into 
which you put them should be previously im. 
mersed in the zinc, then put about four pounds 
of Nails at one time into the basket, and cover 
them well all over with the muiiatic salt ; stir them 
up with an instrument made for the purpose in 
the form of a small spade, leave them say about 
a minute in the Bath ; and when you draw trie 
basket out of the zinc shake it well to eject as much 
as possible the excess of zinc into the Bath, af- 
terwards lake it away, and keep shaking it all 
the time you scatter the Nails upon the ground. 
It is necessary for the articles to be warmed 
before you galvanise them, otherwise they will 
not take well the zinc. 

The most difficult article to galvanise is spring 
Wire made use of for seats of Sofas &c. it re- 
quires to be pulled in and out to prevent the 
zinc from soldering it ; and requires to be well 
beaten to prevent an excess of zinc from form- 
ing on the surface. 

It is well before commencing to use a fresh 
tool to take the precaution of dipping it in the 
zinc : by drawing the article out of the bath 
slowly it gives time for the zinc to run down 
and so not to form into lumps at the end : In 
galvanising all articles such as. Pails &c. it is ne- 
cessary to turn them round and round in the 
zinc that it may be as smooth as possible : in 
galvanising plain sheets of wire-work, the muria- 
tic salt is very apt to fill up the meshes ; it is ne- 
cessary to be well beaten in drawing it out of 
the Bath, and it is more ecomical to have a sheet 
of Iron under the part where you draw it out, to 
be able to catch all the muriatic salt ejected by 
the beating. 

In galvanising an article like the barrel of a 
drum, first dip it in the bath horizontally ; then 
turn it upside down and hand it over to the work- 
man placed opposite ; and on no account for- 
get to turn up the article the reverse way when 
it is out of the bath for the reason before stated. 
When working on a large scale put the zinc 
into the bath over night, whenever your bath 
wants replenishing. 

It is necessary to cleanse the wire work from 
the stains caused by the muriatic salt in the same 
manner as the other articles by washing them 
with a brush and water. 

When it is necessary to galvanise long folds 
of wire work, too long for the depth of the 
bath, it is sufficient to galvanise the half first, 
taking care to beat it well to eject the excess of 
muriatic acid and zinc ; they plunge it in warm 



water, and finish by doing the other half in the 
same manner. 

The lime each article must remain in the zinc 
bath depends upon the nature, and bulk of the 
article, whilst the article is of a slight form a 
shorter time is necessary, than if the article was 
of a great bulk and substance. 

In galvanising Iron sieves they should be im- 
mersed in the zinc horizontally so as to allow 
the muriatic salt to penetrate slowly through the 
meshes oi the wire. 



I consider this the greatest of modern discove- 
ries next after printing and steam, and according 
to my opinion it ought to be as free as the air we 
we breathe, and as far as I have the power, I 
will do my utmost to render it like printing and 
steam of every day use : the great Fulton, like 
all great men never dreamt of protecting his dis- 
covery of the practical every day use of steam 
by a patent ; no, he considered it of too much 
importance to the interests of mankind gene- 
rally to be monopolised by an individual ; and 
such was the conduct and opinion of Sir Hum- 
phrey Davy upon this very article I am now 
writing about, viz. galvanising Iron, &e. lie it 
was who really made the first discovery of the 
preserving influence of zinc when put in con- 
tact with Iron, Steel, &c. he not merely made 
the discovery but he made the application also, 
and died declaring his conviction of ihe great 
practical utility of this his discovery, and regret- 
ted not being able to devote more time to it : He 
acted like Fulton/and never dreamt of a patent: 
the thing is of too much importance to the pub 
lie good, to be teased, vexed, perplexed, or held 
back from their use, by secondary individuals, 
more especially, whilst the great original and 
true discoverer has bequeathed his discovery to 
the public for the benefit of all. Acting upon 
the suggestions and ideas of Sir Humphrey Davy: 
Dr. Revere who is at present living in this City ; 
made a number of experiments as far back as 
the year 1828, and on the 17th March 1829, he 
made a communication upon this subject to the 
Lyceum of Natural History at New-York : he 
likewise sheathed a boat with Iron thus pre- 
pared, and invited the Society to examine his 
specimens at the Navy Yard at Brooklyn ; he 
like his great predecessors never dreamt of a 
patent right, or if he has done so lately, I pre- 
sume it must be the effect of example acting up- 
on him ; for Dr. Revere's communication in full. 
See American Journal of Sciences &c. by Pro- 



8 



PREFACE. 



feasor Silliman of Yale College : for the 1st July 
1829, and page 180. 

I consider this important and very useful dis- 
covery is in the public domain ; I wish to call 
the public attention towards it ; and I hope some 
public spirited and energetic individual who has 
the requisite Funds, will try the thing as regards 
this same patent right : I really consider the pat- 
ent could no more be sustained, than could a pat- 
ent right for some new application of steam; a 
scientifical principal cannot be patented ; I wish 
to state to the public the question as it is ; and 
hope some individual will succeed, who at the 
same time that he gains the right and advantage 
for himself, will likewise serve the public interest, 
in gaining the right for all. 



I am proud to be able to say that I print my 
Book under the moral support, and Auspices of 
two hundred and fifty of the most influential and 
practical men of this great City ; and whose sig- 
natures I have obtained on my canvassing Book ; 
which I think proves clearly, that the publio 
mind wanted to be enlightened, wanted informa- 
tion upon this important subject ; I have endea- 
voured to serve the public to the utmost of my 
poor ability ; and I trust the public will encour- 
age and patronise me by buying my Book ; if 1 
am successful in this my undertaking I intend at 
some future period to publish my views and experi- 
ence upon another subject, equally interesting, bid 
of an entirely different nature. 

New-York, April 1842. 



EXPLANATION OF THE ENGRAVING. 

Letter A.— Pincers for laying hold of any Article to be galvanised, they are 
tamed at the end to prevent the Articles from slipping through j when you dip them 
in the Zinc Bath : length 22 inches. 

B. — Shorter pincers, and used for the same purpose, length JO inches. 

C. — Straight common Pincers, and more convenient for use in some cases, length 
1.5 inches. 

D. — Used for galvanising Wire-work, and made in this form out of Rod Iron. 

E. — Used for galvanising Wire, either coarse or fine, which is simply put on 
the end, and turned round and round in the Zinc Bath. 



ADVERTISEMENT 



As a Book however well and clearly written; 
is after all nothing but Theory: I have seriously 
contemplated to give practical, manual Lessons 
to those who took sufficient interest m this very 
valuable, useful and universally applicable dis- 
covery: to explain, show and demonstrate with 
my own hand everything that does not suffi- 
ciently carry its own explanation: and to the 
apparently just remark: Why if you under- 



stand the business so well : why do you not 
do it yourself? &c. My answer is simple; my 
health is far from robust, and I will not under- 
take anything but what I can do justice to, and 
consequently I am obliged to do the best I can, 
and not as I would otherwise do : When I 
have made my arrangements, I will advertise 
time and place. 

Nexo York, May, 1842. 



INTRODUCTION, 



In this my introduction I will endeavour to clear 
away all doubt that yet remains on the minds of 
ten thousands of individuals in this Country, as 
regards the truth, utility, and goodness of the 
galvanised or Zinced Iron. 

In the course of my successful Canvassing to 
obtain Subscriptions for my Eook ; I have had 
the question often asked me: Thus: What is 
thia ; perhaps it is all a Humbug, &c, and many 
have declared themselves opposed to its intro- 
duction, some from one motive, and some from 
another. 

I will commence with my own positive knowl- 
edge and experience : I declare then upon Hon- 
or that I have a foot Bath, which I have had in 
use for more than four years; for three years, it 
never was a moment without Water in it, and 
under it ; and for seven weeks out of the time it 
was constantly exposed at Sea, to the salt water, 
it has in fact been tried severely ; and I again de 
clare it is now as good as it was the first day I 
took it into use : my Wash-hand Stand, Wash 
Jug, and a large shovel I have had also in use 
for nearly four years ; and they do not exhibit the 
least signs of Rust or Decay. 

As the goodness and durability of the galvani- 
sed Iron, has been proved for the longest Period 
in Fiance; I shall necessarily draw most of my 
proofs out of the Budget, where they are to be 
found the most numerous, the longest tried, and 
the most highly authenticated ; 

Having left Paris so recently as last August ; 
I will state what I know : after a most severe 
and searching inquiry, by a scientifical Commit- 
tee appointed by the French Government; of 
the most capable persons to be found in France 
to judge of the Galvanised Iron ; this Committee, 
rendered its report to the Government in the 
month of May 3841. The Committee, was una- 
nimous in recommending the use of the Gal- 
vanized Sheets of Iron and other Articles for the 
use of the French Navy : The Government has 
adopted, and acted upon the recommendation of 
its Committee : The last question resolved by 
the Committee was how far every article aboard 
a Man of War, in Copper or Brass, can be re- 



placed by similar objects in Galvanised Iron : 
The Committee rendered their unanimous Re- 
port, which was entirely in favor of the Galvani- 
sed Iron, last July : for which see the official re- 
port, published in the " Annales maritimes de 
Brest :" 

As long ago as the 29th of August 1839, Mon- 
sieur LeBaron Seguier, and who is also a mem- 
ber of the Academy of Sciences at Paris : writes 
as follows : 

I have sir ; to announce to you a piece of news ; 
and which I believe will give you much pleasure 
to hear : I have just drawn my Boat out of the 
water; and after having stripped off several of 
the Galvanised Sheets oflron, with which I had 
covered the joints of the longest. Planks, I have 
had the satisfaction to find the galvanised sheets 
oflron, as also the Nails employed to fix them ; 
are in a perfect state of Preservation : It is near- 
ly a year now, sir, since I accepted your propo- 
sition to make the trial of the Galvanised Iron 
under Water. lam happy to be able to attest, 
that after this space of time, no trace of deterio- 
ration can be perceived, «fcc. 

Signed Baron Seguier. 

Not to multiply too much of proofs, I will give 
the following as interesting to Shipping : at the 
same time remarking that I have many others in 
reserve, if it would serve any useful purpose to 
publish them : 

To day 28th September 1840, the undersigned 
having learned that the Schooner LaNorma ; had 
just arrived from the Iceland Fisheries, have 
immediately gone on board to examine if during 
the 5^ months which this Vessel has been enga- 
ged in Fishing, the galvanised Iron which we 
have taken an account of in our Proces — verbal of 
the 6th April, had experienced any deterioration 
from the rust, we have the great satisfaction to 
say that nothing whatever in her iron fastings ; no 
more than in the Chains, and other iron work 
aboard, had experienced the least injury ft om rust. 

That which has appeared to us as much more 
astonishing, as just to this day, we have no 
knowledge that anything has ever been found that 
was able to preserve the Iron from becoming 



10 



INTRODUCTION 



rusted in Iceland : seeing the fish-hooks they 
make use of which are doubly tinned, and in the 
best manner ; yet, even they become generally 
rusted during one voyage : another observation 
that we have been induced to make in favor 
of the galvanised Iron ; is that the caboose chim- 
ney of the Norma, except that it is blackened in 
different parts by the smoke, is otherwise in a 
perfect state of preservation, and it is likewise 
perfectly well known to us, that all the fishing 
vessels which depart from Dunkirk, with sheet 
iron chimnies, bring them back again in such a 
manner eaten away with the rust, that it is total- 
ly impossible to make any further use of them : 
This letter is actually signed by twelve experien- 
ced naval officers and captains, who have been 
in the habit of making long sea voyages. 

The discovery of Electricity by contact, which 
Volta has demonstrated, was amongst the num- 
ber of theoretical discoveries ; but science by 
making use of the discovery, had already found 
out means of drawing numerous advantages 
from it ; natural Philosophy in the first instance, 
and Chemistry afterwards; from it, have deduced 
new Theories, and explanations of various Phe- 
nomena, which were previously imperfectly un- 
derstood. 

All the great men who have honored science 
by their learning ; such for example as Carlisle 
and Nicholson; who were the first who discov- 
ered the Phenomena electro-chemical ; Sir Hum- 
phrey Davy, who has given their name to these 
Phenomena : Berzelius, who likewise has de- 
monstrated the consequences to be deduced from 
it; Ampere who has created the Theory of it ; 
all, have made it the object of scientifical resear- 
ches, and which have considerably enlarged the 
Domain of Philosophy. 

In the mean time, there yet was required, some 
practical application of it, of immediate and gen- 
eral Utility ; Electricity by contact, was up to 
this time, one of those Treasures, for which it 
was necessary to find an application suitable and 
valuable to the various wants of commerce ; and 
what use could it be applied to, of more univer- 
sal interest, than the preservation of Iron and 
cast Iron, and Steel from Rust. 

This universality, presents itself immediately 
to the mind : where is there any branch of Trade 
which has no need of Iron ? Where is there 
an instrument for the use of man, into which 
Iron docs not. enterasan indispensible Element ? 
from the spade and plough, to the most highly 
finished Clock-work ; from the Cottage to the 



most sumptuous Palace, all, all, show the use of 
Iron, all denote its presence ; and certainly, it is 
no more than truth to say it, that to this univer- 
sal use of Iron ought to be attributed the name, 
which is given to the.presentage. Every where 
we turn our attention, Iron is sure to meet our 
view : Stoves, Chimnies, Carriages, Doors, Win* 
dows, Balconies, Window-blinds, Locks, Nails, 
Hinges, Iron Hoops for barrels, Ships, Tools, 
Houses, all just to military Arms, just to busks 
for Ladie3 corsets, the needles they make use of, 
Pens, all are in Iron. 

That we by the imagination, cut off the use of 
iron from all the purposes to which it isat present 
applied, and nothing in the World, would re- 
main standing. This destruction time alone ope- 
rates, and man has more to do to repare his los- 
ses, than to encrease his riches. 

The use of iron has but one limit, viz : its des- 
tructibility ; it is this which has caused us to think 
the ancients were ignorant of the use of it. In 
the midst of ruins, time had concealed it from 
our researches. It was necessary that some few 
specimens which being buried in the depths of 
the Earth, had escaped a complete destruction ; 
were discovered, and thus revealed to us its great 
antiquity. 

To preserve iron from the destructive action 
of the elements, to prolong its durability, for it 
is the rust alone which destroys it, is not this to 
bring to the modern world, an immense Treasure, 
is it not to save them the expense and trouble of 
constantly renewing; to permit them an econo- 
my, an accumulation of strength and Capital, 
which cannot be calculated ? 

And this is not yet all : There are new uses 
for Iron immediately the rust no longer de- 
vours it. Roofing of every kind, for which 
zinc encreases the dangers of a Fire, iron steam- 
boats, rendered universal, raised Terrasses crush- 
ed by the weight of Lead or of Bitumen, Hy- 
draulic Works, Lead for Water pipes,which are 
only used for want of something better, Bathing 
Tubs, where its use is very expensive and con- 
sequently scarce, &c. &c. These are some of 
the new uses for Iron rendered rust proof. 

Professor Dumas of Paris, expresses himself 
thus in analysing a letter written by an Ordinance 
officer of destinction : The land and marine 
service in France had lately a stock of Cannon 
Balls equal to 7,731,000 projectiles, this stock of 
Cannon Balls was valued at more than 2o.000,- 
000 of Francs; This ordinance officer calcula- 
led that after being exposed for 20 years in the 



INTRODUCTION 



11 



open air, a pile of balls is nearly good for nothing; 
now, if we bear in mind that the value of a can- 
non ball sold as old iron, is but one third of the 
original cost, we shall easily see the value of en- 
deavouring to preserve cannon balls exposed in 
the open air, merits every attention on the part 
of Chemists, and natural Philosophers. In admit- 
ting that the French Government might galvan- 
ise all their stock of balls (which they now do) 
and which would cost but little to do it, and 
would no more be liable to rust, it results from 
the calculations of this Ordnance Officer, an 
economy of 17,333,334 francs for 20 years, for 
this part only of the war department. 

I think it important in this place just to notice 
a peculiarity and likewise the very great danger 
in covering any building with Zinc ; as it cannot 
be too universally known, the immense risk that 
persons run who through ignorance of the pro- 
perties ofzinc, have their Dwellings and Manu- 
factories covered with it : I will copy part of a 
letter that I have in my possession, at the same 
time just noticing, that I have a dozen, if one is 
not sufficient. 

A fire took place at Amiens in France in No- 
vember 1840, in a large Linen Manufactory: the 
letter runs thus : by the carelessness of a work- 
man a gas lightsetfire v to some flax that they were 
drying in a warm room, the flames having bro- 
ken the windows, communicated immediately to 
the roofing ; which was covered with zinc, this 
zinc immediately caught fire and burnt with so 
much rapidity, that neither the woodframe, nor 
even the thin planks of very dry deal wood were 
but slightly damaged by the fire, in every part 
that the burning manifested itself; although there 
was not a vestige of the zinc remaining, which in 
a few minutes, had been entirely consumed, 
without having had the time to set fire to the 
wood. 

The galvanic paint powder, although more 
limited in its application, nevertheless, is capable 
of being rendered very useful ; as for example, 
in sending goods by sea, take what precautions 
you will it is impossible to preserve from rusting 
all articles in the hard-ware line, &c. The rust 
is a cause of much loss to the owners, and the 
price at which they are able to sell their goods, 
ought necessarily to be enhanced, in future ; 
they may use the galvanic powder by covering 
the articles with this powder, or to envelope 
them with a coarse paper that has been prepar- 
ed with this powder, or otherwise to rub the 
powder over the articles, will be sufficient to 



guaranty them from the effects of the Humi- 
dity. 

We see then the great extent to which the ap- 
plication of galvanising maybe employed ; be- 
sides roofing boats, bathing tubs, stove pipes, 
hydraulic pipes, gas pipes, in which last article 
the advantages of galvanising are lightness, 
economy, and durability ; are often expend- 
ed immense sums of money. The paint also 
presents no less advantages; taken alone it would 
be sufficient to sell it at the price of ordinary 
paint, to realise a very great profit, and who 
would refuse to give it a preference ; its supe- 
riority being so well established. 

Experience has demonstrated that the iron is 
preserved from the rusting action of the air and 
of dampness ; not only on the parts which are 
covered by the zinc, but even in the parts which 
remain uncovered whilst these parts are not far 
removed from the zinc ; forexample, in the part 
which is cut off the sheets of iron, which have 
been zinced ; provided, that the thickness of these 
sheets does not exceed I or £ of an inch, it is suf- 
ficient to note such a property to be able to ap- 
preciate all the value of it. 

We know to-day, that in putting in contact, 
one with another, under suitable conditions, two 
different metals, the one most liable to rust, pro- 
tects the other from the action of the rusting pro 
perties of the air, humidity and saline dissolu- 
tion, &c. 

It is to Sir Humphrey Davy, that we owe the 
discovery of this principle, so fruitful in useful 
consequences, this learned man, also pointed out 
and noticed the employ of zinc to preserve iron 
and steel from rusting, he even demonstrated the 
efficacy of these means, in showing, that instru- 
ments, the most highly polished, remained per- 
fectly free from the rust, whilst they kept them 
shut up in sheaths and cases lined with sheets of 
zinc. 

In tinning iron, the iron is rendered more lia- 
ble to rust by the contact of the Tin, than whilst 
it is entirely bare, in such a manner, that when 
the Tinning is not performed with greatest care, 
the parts which are bare scale off and corrode in a 
very little time ; in the galvanised or zinced iron 
to the contrary, the iron is protected by the zinc, 
not only every where that this metal covers it, 
but even in the parts which by consequence of 
the imperfection of the operation, have remained 
bare of the zinc ; it is this very valuable property 
which characterises it. 
They can galvanise or zinc every article in 



12 



INTRODUCTION 



iron, &c, no matter what it is, after they have 
given them any form they like. 
TJte following remarks are true as regards Paris, 
France. 
The galvanised sheets of iron are not dearer, 
at the same weight, than the sheets not galvani- 
sed ; they are near about the same price as zinc 
in sheets, but besides, that they are much more 
tenacious and more flexible they have besides 
all these advantages, the oue of not melting, and 
not becoming inflamed in the unfortunate event 
of a fire as the zinc does, 



The galvanic paint powder .can be sold in 
trade at a very low price, because it is made 
from the impure residue of the melted zinc. 

Now what is true as regards France, will like- 
wise be true as regards this country, after a lit- 
tle practice for I know of no valuable reason to 
the contrary : and that it may very soon be real- 
ised is my most sincere wish, I wish for nothing 
more sincerely than to see the welfare and pros- 
perity of this country promoted especially when 
it can be done so easily, by an useful and me- 
chanical, and philosophical discovery like this. 

New-York, April 1342. 



THE ART OF PRESERVING 



IRON, CAST IRON, AND STEEL, 



FROM THE 



ACTION OF RUST BY GALVANISATION. 



It is a question so important, the preservation 
of Iron from rust, that from a time immemorial 
the learned men of different Countries, have tried 
to find out the means the most efficacious : 
they have tried different substances to cover the 
surface of the metals ; such as oily and greasy 
substances, and likewise divers varnishes ; lately 
a French Chemist Mr. Dumas pointed out to the 
Academy of Sciences at Paris, a varnish made 
of India Rubber, and Mr. Pay en the employment 
of alkaline solutions. 

These diverse varnishes have the inconve- 
nience of not adhering sufficiently to the metals, 
and to wipe, and to scale or chip off more or less 
easily, in this case, the parts of the Iron or Steel 
left bare of the varnish, rust rapidly. 

In consequence of the great discovery made by 
Galvani and Volta ; of the electricity, developed 
by the contact of two metals of a dissimilar na- 
ture ; in perceiving, that one of the metals which 
composed the pile of Volta, was always preserv- 
ed from the rust: the preserved metal, is always 
that of the two, which has the least tendancy for 
rusting ; consequently in the ordinary Tinning of 
Iron converted into Tin ; it is the Tin, which is 
preserved from the rust, to the detriment of the 
Iron : thus : in this case, the Iron is much sooner 
pierced by the rust, than if it had never been 
tinned ; in the ordinary tinning of Iron, the iron 
is always electrified positively, whilst by the new 
discovery it is electrified negatively. 

The first learned man whose attention was 



drawn to this phenomenon, was the late celebra- 
ted Sir Humphrey Davy, who proposed the ap- 
plication of the Galvanisation, to preserve Cop- 
per from the Corrosion of the Sea-water. 

They tried Sir H. Davy's plan, but in a very im- 
perfect manner, for the coppering of the Men of 
War, &c. the manner employed, consisted in 
adjusting pieces of zinc, of Iron, of cast Iron, or 
of Nails, made of these metals, on the Copper, 
that they wished to preserve from the destruc- 
tive action of the Sea-water : Sir II. Davy tried 
likewise, a few years ago, to preserve Tin 
from rusting, by means of Galvanisation, but in 
pursuing always the same plan, whose principal 
inconvenience, consists in a difficult and restrain- 
ed application, and only well preserving from 
the rust, those parts, in immediate contact with 
the zinc. 

The means that I am going to describe is also 
based on the property of the contact of two met- 
als of a different nature ; but the application of 
the principal, is very dfferent, and the manner 
of applying it, is suitable to every article. 

This new discovery, is applied in several man- 
ners, having each of them, their particular man- 
ner to preserve Iron, cast Iron and Steel from 
the action of the Rust. 

See here: the three principal manners of ap- 
plying this new discovery ; first by way of zinc- 
ing ; secondly by painting, thirdly in covering 
the articles, that they wish to preserve from the 
Rust, with the galvanic powder ; likewise a 



14 



GALVANIC ZINCING 



fourth manner of applying the same principal, to 
preserve from Rusting Iron articles that have 
been polished, on file without changing their 
metallic appearance ; this means consists, in rub" 
bing the articles with a paste : 

I will now describe, in the clearest manner 
possible the Art and Secret of galvanising the 
Iron, in following the sam© order as that I have 
just named, for the divers ways of galvanising : 



GALVANIC ZINCING. 

This galvanic Zincing consists first in covering 
completely the surface of the Iron, with a coat of 
Zinc, and secondly in covering the Zinc with a 
coat of pure Tin, or mixed with Lead, the 
second tinning is optional, the object of it is, to 
preserve the Zinc in certain cases. 

Decapage or cleansing the Iron of its outer Coat, 
and preparing it before it is covered with the Zinc. 

To apply the galvanic Zincing, they com- 
mence by well cleansing the Iron that they wish 
to galvanise ; all the ways for cleansing the Iron 
are good, but the manner that has the best an- 
swered for me, is the immersion of the Iron in 
acidulated water, the water is diluted with the 
sulphuric Acid reduced to 10 degrees of strength ; 
easily ascertained with the instrument, for test- 
ing acids. It is well also to try to employ the 
acidulated water at different temperatures : 

They warm the acidulated water in Vasses of 
Lead, or you may employ it cold in wooden 
Tubs, and they there put the Iron; if it is in 
Slieets they place them on a land of frame ; which 
permitsthe acidulated water to penetrate in every 
part ; they do not leave the Iron in the acid, but 
just a sufficient time, to cleanse it from the Rust 
or outer coat, in taking it a piece at a time, to 
cleanse it over again with sand or pounded stone, 
in rubbing it with a piece of Cork ; they wash 
the Iron making use of a brush for that purpose, 
as soon as the Iron appears cleansed from the 
Rust or other impurities ; after that it appears 
clean, it is then put in water ; small articles such 
as Nails, have no need to undergo this operation ; 
they leave them a little longer in the acid, and 
afterwards wash them : 

Iron prepared in this manner, can remain, 
if it is necessary for a month in the water with- 
out sustaining any damage ; it will not be spoil- 
ed ; it is not the same after the following opera- 



tion : this operation consists in moistening the 
Iron piece by piece, if the articles are not two 
small, in a solution of ammonical salt, or pre- 
haps, that which is preferable in water acidu- 
lated with muriatic acid. 

They put about half acid and half water, and 
they dry immediately, the articles moistened or 
dipped in this acidulated water, and they zinc 
them in the promptest manner possible, for two 
hours after the immersion in the muriatic acid, 
the Iron would be rusted, in such a manner, as 
not to be possible afterwards to be zinced ; ("they 
will be able to dry the articles by placing them 
in an Oven, of which I will speak in another 
part. 

Zincing of Iron in Sheets and large pieces. 

The first Tinning is performed with Zinc ; 
they ought to melt the Zinc, in an Iron or cast 
Iron Cruset, but furnished in the inside with 
bricks, or an earthy coating such as Clay, to hin- 
der the contact of the Iron with the melted zinc, 
for otherwise it would be a mixture of Iron and 
Zinc which would render the Zincing impossi- 
ble ; they have made use of Vessels in cast Iron 
of a rectangular shape, similar to those that they 
make use of for Tinning; they have placed in 
the inside bricks well cemented with Clay : 

The covering with the zinc, is performed m 
the following manner: the zinc being melted, 
they skim it well, and then cover the surface 
with muriatic salt or ammoniacal salt (but the 
muriatic salt, is not much more than half tho 
price of the other and answers quite as well, in 
powder, or with any other salt of the same na- 
ture, that done, they introduce, in the melted 
metal ; the pieces of Iron prepared as I have des- 
cribed before ; they balance them for a moment 
in the bath, and they draw them out slowly, that 
they may not be loaded with Zinc, afterwards, and 
before the Zinc is become hard, they throw the Zinc- 
ed pieces in pure water, and as quick as this im- 
mersion, they icash them with a sponge or a brusk, 
and they dry them immediately in putting them into 
saw-dust or bran. 

This operation of the immersion, and washing 
immediately afterwards the Zinced articles, is of 
the greatest importance, as without this precau- 
tion, the articles would become blackish in places, 
in such a manner, that, it would be impossible to 
sell them in trade ; on the contrary prepared as 
it is described above, they become as wH5te 
as silver : they may obtain them whiter yet, in 
plunging them rapidly in water acidulated with 



GALVANIC ZINCING. 



15 



the sulphuric acid before having plnnged them 
in the pure water. 

The bath of melted zinc, ought not to be very 
warm : they ought to commence the zincing a 
little time after that it is entered in fusion; if the 
bath was too warm, it would burn and evaporate 
very soon the muriatic salt, which ought con- 
stantly to cover the bath, they can likewise di- 
minish the consummation of the muriatic salt, 
when the size and nature of the pieces that they 
prepare, permits to reduce the surface of the 
bath ; they can easily diminish the surface in there 
placing some bricks, which swim on the melted 
metal. 

When they prepare Sheets of Iron of small 
dimensions, such as those of the size of Tin, 
they zinc several of them at the same time (six 
for instance) they place them on a grating, that 
they hold with two handles ; the Sheets ought 
not to touch one another ; they hinder their con- 
tact by Iron Wires turned back, and fixed on the 
grating by the two extremities, and placed be- 
tween each sheet. 

In order to lose, the least possible time, of 
combustible, and of muriatic salt, they ought to 
employ two workmen on each bath: they are 
placed opposite to one another, and furnished 
each with a handle or instrument proper to lay 
hold of the articles ; for the large pieces they in- 
troduce them in the bath one and one, with a pair 
of pincers or tongs, of which the part that grasps 
the articles should be pointed in order to leave 
the least possible traces on the zincing ; they 
ought to introduce the large pieces, very sloicly 
in the bath ; without this precaution there would 
be an explosion, and projection of the melted 
zinc, which is of course very dangerous ; for 
the preparation of very large pieces, they will 
make vise of a Crane furnished with hooks; the 
Crane in its circular movement will carry the 
pieces in the bath of metal, from the bath in the 
water, and from the water to the place where 
they can be cleansed from the spots caused by the 
muriatic salt. 

Flattening the Sheets of Iron. 

The sheets which become deformed by the ef- 
fect of the too great heat of the zinc bath, or of 
which the surfaces are too uneven, they put 
them under the Flattener, but that they may not 
become more deformed in passing between the 
Cylinders, they are obliged to sprinkled them 
all over with Ashes, with Rosin or any other 



substance in powder, that can be employed to 
hinder the Cylinders from gliding or slipping on 
particular parts ofthe sheets. 

Preparation and Zincing oj small articles such as 
Nails, Chains 8fc* 

They prepare these articles previous to being 
zinced, by the processes I have described for the 
large pieces, and for the iron in sheets ; only In 
the place of rubbing and cleansing them with 
the pounded stone or sand, they stir them 
from time to time in the acid, to enable the 
acid to act on every part, and likewise, by 
the rubbing one against another, the Rust 
may become cleansed from the different pla- 
ces ; it would be well when they work on a 
large scale, to cleanse the small articles in a 
barrel that they would make to turn on an axle- 
tree ; or otherwise, without cleansing the small 
articles in the barrel, they can put them in the 
barrel after the cleansing, and at the first wash- 
ing in the water. 

The articles thus prepared pass to the muri- 
atic acid, and dried in the oven of which I shall 
very soon have occasion to speak, they will pro- 
ceed to the zincing in the following manner : 

They put in a considerable quantity of the 
small articles in the mettled zinc, and covered 
with the muriatic salt, and after having left them 
there a moment, they draw them out slowly with 
an iron skimmer, and by small portions, for that 
they may of themselves discharge as much as 
possible the too great quantity of zinc, that they 
are apt to retain. 

The articles after this operation are soldered 
one to another, and retain yet too much zinc, 
but to clear them of this excess, and to unsolder 
them, they put of them, a quantity in an oven, 
they cover them with Charcoal, and they keep 
them very hot for about a quarter of an hour, 
they stir them up from time to time, with an iron 
rod or poker, just to such a time that the articles 
may have sufficiently discharged the too great 
quantity of zinc; then they put them on the 
before part of the oven, with a kind of iron 
rake, and they continue to stir them just until tlte 
zinc is become solidly attached ; afterwards they 

* I mean here small Chains for the large ones 
are prepared by the same process that is followed 
for the large pieces, they shake them well as 
they can out of the bath, to hinder the different 
Links from becoming Soldered or sticking to- 
gether. 



16 



GALVANIC ZINCING 



spread them on the ground, or in water, and they 
wash them in the water, and afterwards in the 
water acidulated with the sulphuric acid ; they 
must not be left too long a time in the acid, 
otherwise thezinc would be very soon dissolved; 
after the acid they wash them in the pure water* 
and they dry them in saw-dust or in bran, 
or they dry them on the oven, in a place that 
they have made expressly for drying before 
and after the zincing. 

The pieces being dried, they move them in a 
bag or in a barrel turning on an axletree, in or- 
der that by their mutual friction they may polish 
one another. 

The zincing of small articles, particularly 
Nails, ought to be done in a small vessel, in order 
not to mil the risk of spoiling too great a quan- 
tity of zinc, for if they forget and leave too 
long a time the Iron articles in the hot zinc, it 
will become unfit to be any longer used for 
zincing. 

The zinc that they use for zincing ought to be 
as pure as possible, you can easily discover, the 
quality of it, in breaking a piece ; it will be as 
much more pure, as the parts are more brilliant 
at the place where it is broken. 

This trial ought to be made with zinc that has 
not been rolled or flattened: they employ zinc 
of an inferior quality, or the zinc that has been 
spoiled by the Iron, to make the galvanic pow- 
der of which I will speak in another place. 



Galvanisation of Iron Wire. 

They galvanize iron Wire, in making it pass 
horizontally in the melted zinc that is covered 
with muriatic Salt ; they proceed in the follow- 
ing manner, the iron Wire being prepared, and 
cleansed from all impurities, having passed 
through the muriatic acid, theyunrol it on a cy- 
linder turning on its axletree, and they hook one 
of the ends of the Wire to another cylinder 
similar to the first, they then turn the empty 
cylinder, at the same time the wire in passing 
•from one cylinder to the other, passes through 
the melted zinc, on which there is an obstacle 
which forces the Wire to pass through the zinc 
bath; after this operation they clean the Wire, 
in the same manner that I have described for 
the other articles ; besides that they may pass it 
by the Wire-drawer, or rub it with emery paper. 

* They can without injury to the articles sup- 
press the washing with the acid and water. 



The Double Zincing or Tinning. 

The double zincing is not necessary, only on 
Iron in Sheets or large pieces of wrought or 
cast Iron, besides the necessity for the double 
zincing can but rarely be required ; it will only 
be requisite in very rare cases, where the single 
zincing would be destroyed, by the contact of 
certain substances, or otherwise if it was re- 
quired to make Vases that were wanted to con- 
tain acid substances. 

Nothing can be more simple than the zincing 
or tinning of pieces that have been already 
zinced; they use for this object pure tin or it 
may be mixed with lead ; they can put say two 
thirds of lead ; they dissolve these two metals 
in a cast iron vessel, and they introduce therein 
the pieces that they wish to tin ; in the mean- 
time, it is necessary, to succeed, to follow with 
the greatest care, the process that I am going to 
describe in a few words : They pass over the 
pieces that they wish to tin, a sponge or a brush 
moistened in a solution of ammoniacal salt, or 
what is still better in the pure muriatic acid, and 
they plunge the pieces, thus wet or moistened, 
in the bath of tin, which must be covered with a 
considerable coat of suet or grease, (at the least 
two inches,) the bath oughttobe very hot, nearly 
sufficient to burn up the grease; they ought to 
introduce the articles in the tin, one by one, and 
very rapidly, hut to take them out again immedi- 
ately and slowly so as to give sufficient time for 
the tinning to take effect; mind it is not necessary 
to take out the articles too slowly, for the zinc 
would otherwise melt off from the zinced articles, 
and would thus spoil the bath of tin; besides the 
articles deprived of the zinc would not be gal- 
vanised. 

Immediately after the tinning, and whilst the 
articles are yet warm, they cleanse them with 
saw-dust or bran. 

They can likewise apply the manner of tinning 
that I have just described upon zinc that has been 
rolled or flattened ; by this means it will be much 
whiter, and less liable to Rust, but it will have 
its other imperfections; it is better to tin the 
zinc in the condition or form it is in after being 
melted, and to flatten or roll it afterwards ; by 
this means it will be smoother, and will take less 
tin. 

Galvanic Powder : the manner of making it. 

The galvanic powder is simply zinc reduced 
in powder, they make use of the galvanic pow- 
der in several manners to preserve Iron from 



GALVANIC ZINCING 



17 



Rusting: first as paint: secondly in powder; in 
placing under the powder the articles that they 
wish to be preserved from rusting : thirdly, in 
forming with this powder and other substances 
a kind of paste, to rub iron articles that they 
wish to preserve from the Rust ; before entering 
in the details of these divers processes, I will 
first describe the manner of making the galvanic 
powder- 
It was no small difficulty to overcome, that of 
reducing the zinc into powder, and at but a 
trifling expense ; at the same time after repeated 
trials and experiments, I have been very suc- 
cessful, and have completely succeeded. 

To make powder of zinc, they put the zinc 
intended for this purpose in a vessel they hinder 
from penetrating in this vessel any current of 
external air, which would be likely to increase 
the combustion of the zinc, and they augment 
the heat of the melted zinc, nearly until it 
becomes red hot, afterwards they skim the 
zinc, and then cover it with ammoniacal salt, 
and immediately afterwards, they put into the 
melted metal, in taking care to stir it up continual- 
ly, 07ie tenth part of its weight of wrought iron 
filings, and not cast iron filings : before putting 
it in the zinc, the iron filings ought to be mois- 
tened with muriatic acid, after the introduction 
of the iron filings, they cover the surface of the 
metal with fine charcoal powder, and they in- 
crease the heat of the melted metal, until it be- 
comes a white red ; they keep it at this heat for 
about quarter of an hour, in stirring it up from 
time to time with a poker, afterwards they draw 
out the mixture with a help of a rake ; using it 
to raise up a brick that serves to let you see into 
the mixture and the melted metal is conveyed 
into a reservoir of Cast Iron, or reservoir 
formed of bricks that is lined with an iron coat- 
ing to hinder the combustion of the zinc : that 
done they ought with the aid of an iron poker or 
bar which passes through the cast iron cover, 
and in which they have left a hole expressly to 
enable you to stir up the mixture, until such 
time that it becomes solid, this mixture, thus be- 
come solid, is the galvanic powder. 

Galvanic Paint. 

This paint, as likewise the galvanic Zincing, 
possesses the invaluable property of perfectly 
preserving Iron from the Rust. 

The galvanic paint is composed of galvanic 
powder, well reduced in powder by means of the 



Painter's Muller, and diluted with liquids such 
as are generally used for preparing paint and 
varnishes ; every kind of substance answers as 
much better as it is a good Conductor of the 
galvanic fluid ; I have made very good paint, 
with the Oil proceeding from the distillation of 
coal Tar, such as is produced in the Gas Works* 
The coal Tar itself is not bad in mixing with it a 
third of Turpentine to facilitate its drying, but 
on account of the strong smell, it cannot be em- 
ployed for all kinds of articles. They can also 
make use of a greasy varnish, but then there 
would be the inconvenience of its being too ex- 
pensive, they might likewise make use of Lin- 
seed Oil as is done in preparing the common 
paints, although this Oil does not altogether favor- 
ise so much the galvanic effect of the z there 
would not be in fact, any impropriety, in put- 
ting in the paint, either Minium or White Lead,, 
to give a body to the paint : 

The galvanic powder is employed also in oth- 
er forms than paints, as in powder to preserve 
from Rust, all iron articles that have been polished 
or filed, and also other articles, such as those em- 
ployed by Watch-makers, the Hard-ware Trade, 
&c. it is only necessary, to preserve these kinds? 
of articles from the Rust, to place them in the 
galvanic powder in the position they will be 
preserved from rust, even in the case of their 
being exposed to the water. 

They can also form with the galvanic powder 
a kind of paste, to rub over polished or filed iron 
articles, that they would wish to presesve from 
the Rust, this paste is made with Wax, that 
should be melted and into which they put ten 
times as much galvanic powder, and about 1-50 
part of Suet or Oil ; I ought just to notice in 
this place, that this paste does not produce any 
wonderful effect : 

They can likewise make with the galvanic 
powder a paper proper to envelope polished 
Iron or Steel articles, that they would wish to 
preserve from the Rust; they would also be able 
to make a galvanic paper of an inferior kind, for 
the purpose of wrapping up all Iron articles, to 
preserve them from the Rust ; they can make 
this paper in putting zinc that is ground to an 
impalpable powder in the paste of the paper at 
the time it is being made, or in sprinkling the 
powder all over common paper that has been 
prepared with a gluey or sticky substance, such 
as Gum Arabic, or flower paste, but not size., as 
the size will cause the Iron to Rust : 



18 



GALVANIC ZINCING 



The preservation of Iron by this process, is 
not owing solely to the galvanic fluid, of which 
the action ceases very soon in consequence of 
the oxydation of die zinc, which itself is electri- 
fied positively. 

It is the Oxyde developed by the galvanic con- 
tact, which attaches itself with considerable 
strength to the zinc, and likewise to Iron which 
has become bare, which preserves it from the 
Rust, in the same manner as an indestructible 
varnish would do : they can make the coat of 
this oxyde more solid yet, in forming it artificially 
by the help of a chemical agent. That which 
has the best succeeded with me is a dissolution 
of ammonical salt, with which they wet the 



metal, after it has been cleansed with gritstone 
reduced in powder ; by moistening and rubbing 
it with a rag, by the employ of the muriatic salt, 
it forms of itself on the metal a hard coat of muri- 
ate of zinc, perfectly iudissolvable in the water, 
which covers and preserves the Iron from Rust, 
in the same manner as a superior varnish would. 

END 

Of the first Series of Instructions for galvani- 
sing Iron, Steel, &c, but experience having 
suggested many Additions and new discoveries, 
see the 2d Series of Instructions, and likewise a 
great deal of additional matter and information 
connected with them. 



PRACTICAL INSTRUCTIONS 



FOR THE 



GALVANISATION OF IRON. 



Decapage, or Cleansing the Outer Surface. 
The decapage is done ; in oblong wood 
troughs that are strongly made, and well hoop- 
ed with Iron Hoops, and lined in the inside 
with Sheets of Lead; they may at the same time 
dispense with lining them with Lead, the troughs 
are made out of heart of Oak ; but with wooden 
troughs, that are lined, you have the inconveni- 
ence of not being able to depend upon them, on 
account of the risk of their splitting, the oblong 
shape is best suited for the decapage of long 
sheets of Iron. 

They ought before commencing to use the 
wooden oblong troughs, to paint them over 
with several coats of paint, or mineral tar ; 

The best possible Acid you can use for decaping 
the Iron, is without contradiction, the acidulated 
water that has served for purifying Lamp Oil. 

This acid possesses the very valuable property of 
decaping the Iron, without injuring or corrodin, 
die metal ; and moreover it can be purchased for 
nearly nothing, as it is after it has performed its 
office of purifying the Oil, and consequently no 
longer of the least value to them, that it becomes 
useful for decaping the Iron ; in general persons 
would be glad to be rid of it, in that case it will cost 
the price of the Cartage, and no more ; if they can- 
not procure a sufficient quantity of this Acid, it 
would be necessary to mix it with the ordinary acid- 
ulated icater; it will communicate the same pro- 
perties to the water, if it is employed but in small 
proportions. 

In case of not being able to procure any acid- 
ulated water of this kind, they make use ofmu- 
riatic or sulphuric acid mixed with water, the 
decapage is done equally well with either of 
these two acids, but the sulphuric acid is the 



most economical, although the first cost is more : 
the sulphuric acid, has the advantage over the 
muriatic acid, of lasting a longer time, without 
the necessity of being so often renewed, or 
which comes to the same thing, of serving to 
cleanse a greater quantity of Iron, for the same 
quantity of acid ; moreover they can sell the 
residue of the decapage, which is the Sulphate 
of dissolved Iron.* 

It is advantageous to heat the acidulated water; 
the heat augments the action of the acid on the 
Iron, and permits a less quantity of acid in the 
water ; the strength of the acidulated water ought 
to vary from 10 to 15 degrees of the instrument 
for trying the strength of acids ; it will require as 
much less strength, as the acid is more heated ; 
they warm the acid; either in causing Steam to 
pass throughsmall pipes ; serpenting in the clean- 
sing troughs, or by means of a lead vessel con- 
taining boiling water ; that they put into the 
acid, this Lead Vessel is similar to what they use 
for warming the water, at the Bathing Rooms. 
The sheets of Iron, ought to be placed on a 
kind of frame in the trough, as without that the 
acid would not be able to penetrate in every 
part, that they ought likwise to move them from 
time to time, to change the points of contact of 
the sheets of Iron. 



* To make the most of this Sulphate of dis- 
solved Iron, which is difficult to remove on ac- 
count of its weight as a liquid, and likewise dif- 
ficult to sell on account of its being dissolved ; 
it will be well to crystallize it ; for this purpose, 
they will put it in a Leaden Vessel, and place it 
on a Stove, they will add to it some Iron clip 
pings or iron filings, to completely saturate all 
the acid, afterwards they will leave it to crystal- 
ize in the oblong Troughs. 



w 



GALVANISATION OF IRON. 



The, second Operation is the Washing in Lie- Water. 

The washing in the lie-water will not be ne- 
cessary, only in case of having made use of the 
acidulated water, which has served to purify 
Oil ; this acidulated water will always retain a 
greasy or oily substance, which becomes attach- 
ed to the articles, and hinders the zincing from 
taking effect. The lie-water is made with pot- 
ash, or with pearl ashes, they make it have a 
strength of about 6 to 8 degrees]of the Areometre, j 
and they warm it in the same manner that I have 
■described for heating the acids. 

After having rinced the cleansed articles, they 
put them for a minute in the lie-water, and then [ 
scrub them with a brush to cleanse them from 
all the greasy particles. 

The third operation, Second Decapage. 

The second decapage is done with the muria- 
tic Acid mixed with water, this second cleansing 
has for object, to take off whatever might yet re- 
main of oxyde on the articles ; this acidulated 
water ought to have about 10 to 12 degrees of 
the strength of the Areometre, 

They can dispense with heating this acid; 
they leave the articles during several minutes in 
the acid, and they then draw them out, to exam- 
ine if there yet remains any oxyde attached to 
them, if there is any, they take it off in nibbing 
the places with apiece of gritstone, which they 
moisten with pure muriatic acid ; the gritstone 
or porous stone is the kind that I have found to 
answer the best for this purpose : if indepen- 
dently of the spots, the articles are not perfectly 
white, they brush them with a brush and sand 
or gritstone reduced to powder diluted with the 
acidulated water, that has been acidulated with 
the muriatic acid: afterwards they rince the ar- 
ticles in water, to cleanse off the sand ; from 
there, they carry them to the trough, which 
contains water that has been slightly acidulated 
with muriatic acid. 

This water ought to have about six degrees 
of strength of the Areometre, it will be neces- 
sary to dissolve in it a little zinc, and likewise to 
put in it a little muriatic salt. This composition 
gives to the iron the property of attracting less 
zinc. 

The fourth operation is the drying, 

I ^mediately after the last cleansing, they carry 
the articles to the drying oven to be dried) it is 



not necessary that they remain in the oven a 
moment after they are dry, for, in that case, they 
would become rusted, and the zincing would be 
badly done ; it would be better even to zinc 
them whilst they weie yet moist; the drying is 
done in a brick oven, heated with coke or char- 
coal. 

Fifth Operation, the Galvanic Zincing. 

Immediately after the drying, and without any 
time of stopping, it is necessary to zinc the arti- 
cles whilst they are warm. 

This is the way to have superior and beauti- 
ful articles, and consequently to have more bu» 
siness to do ; for the articles that are warm can 
be zinced more promptly, and the more they 
zinc the articles quick, the less will the articles 
become loaded with zinc. 

It is necessary that the bath of melted zinc, in 
which they zinc the articles, should be complete- 
ly covered with the muriatic salt ; except for the 
galvanisation of nails! but it is absolutely ne- 
cessary for all kinds of wire-work and iron-wire J 
they use the muriatic salt reduced in powder, 
that they keep throwing from time to time on 
the bath, with a spoon. 

It is of an immense importance for the eco- 
nomy, and for the quality of the productions, to 
work at a suitable temperature ; but to know 
exactly the temperature at which they ought to 
work, it would require a pyrometer, or a ther- 
mometer, and unfortunately there is no such an 
instrument to be had that would tell you exactly 
the temperature of the melted zinc ; by and by 
such an instrument will be discovered ; as soon 
as it is, I will make it known, and likewise the 
manner of using it : in the meantime, I will say 
that the temperature which appears the most 
suitable, is that at which the kind of scales, 
which form on the articles, when the bath is too 
cold, have disappeared; less heat, gives a heavy 
covering of zinc, and covered with scales; and 
more heat gives a thick and fragile zincing, and 
likewise deforms the articles, particularly if they 
are sheets of iron or utensils of a slight make, 
and moreover consumes much more of the mu- 
riatic salt. 

It is necessary always to introduce the articles 
into the bath, in the quickest manner possible, 
and to draw them out again directly, but slowly, 
that the articles may not draw with them too 
much zinc. 

Ail these observations are of great importance, 



GALVANISATION OF IRON. 



2J 



particularly for sheets of iron that they intend 
to be manufactured after the galvanization. 
The articles being drawn out of the bath, they 
throw them in the water to facilitate the cleans. 
ing them of the muriatic salt, that the zincing 
retains ; but it is necessary to pay attention not 
to throw them in the water too soon, for in that 
case, the zincing would be rough and covered 
with small globules ; it is necessary before 
throwing the articles in the water, that the zinc- 
ing may have had time to become settled and 
solid. 

I will describe in this place, the manner to 
galvanize nails, and iron-wire, for the reason 
that these articles are not galvanized in the same 
manner as the other articles; see, as follows: 
the manner to galvanize nails and all articles of 
a similar nature. 

For these articles they do not put the muriatic 
salt on the bath, they take the nails whilst they 
are well cleansed and dried, and they put them 
in an iron-wire basket, or in a basket made of a 
sheet of iron pierced with a great number of 
holes ; they hold the basket by a long wooden 
handle, and they introduce it into the bath, after 
having sprinkled the articles all over with muri- 
atic salt : whilst the articles are in the bath, they 
keep stirring them with an iron poker in the 
form of a small spade ; and at the moment of 
drawing them out, they sprinkle them afresh 
with the muriatic salt, afterwards they draw 
them out, and they shake them well to take off 
the excess of zinc, and they throw them, at the 
same time keep shaking them, upon an inclined 
plane of sheet-iron, which conducts them into a 
tub of water. 

To separate the articles that are soldered one 
to another, and which ought to be distinct and 
as clear of the zinc as possible, they put the 
whole into an iron sieve, of which the holes are 
large enough to let pass the single articles, and 
retain those which are soldered to one another. 

The iron-wire is galvanized in the following 
manner: before decaping or cleansing it by 
means of the acidulated water, they divide it into 
small bundles, in each bundle they tie the two 
extremities of the wire together, and they put 
one or two ties loosely, to hinder the wire from 
becoming entangled; they are then cleansed 
and dried, and they introduce the articles one 
by one into the bath, in holding them on an 
iron-rod (See Engraving, letter D,) made at one 
end into a semi-circular shape, they keep turn- 
ing it constantly in putting it into the bath, and 

2 



likewise when they draw it out, in order that 
the wire may not become soldered together, and 
when they are zinced, they throw them in the 
water. 

The zincing ought to be done in crusets in 
wrought, and not in cast iron. Length of the cru- 
set in english measure, 6 feet, 3 inches. Depth of 
the cruset, 3 feet, 9 inches. Width of the cruset, 
2 feet at the widest part, or the middle, as the 
shape is an oval. The oval form is that which 
suits the best to galvanize articles of every form 
and shape, and with the least zinc possible in 
fusion, and besides the crusets of this shape re- 
sist very well to the pressure of the melted 
metal. 

They fix the cruset on the grating of a brick 
oven, which leaves at the sides, between it, and 
the cruset, a space of four or five inches destined 
to receive the combustible that they put in at the 
top. This fuel ought to be coke or charcoal, 
but the coke is the most economical; they make 
horizontally several rows of holes on the cruset ; 
these holes ought to be of the size of two brick- 
ends, they close up with brick-ends these holes, 
and likewise the doors for taking out the ashes 
ought always to be shut during the time of 
working ; the workmen ought not to open, only, 
the holes of the upper row, when they want to 
regulate the heat of their bath ; the other holes, 
aud likewise the doors for taking out the ashes, 
ought not to be opened but once a day ; to clear 
out the ashes. 

They ought to close them afterwards, and ce- 
ment them with the greatest care with moist clay 
and brick-ends; without taking these precau- 
tions, they would burn the cruset in a little time, 
and besides it would cause to rise to the surface 
of the bath, the residue of the zinc which had 
sunk to the bottom, and the zincing performed 
under these circumstances would be the worst 
possible, and likewise the articles would take a 
greater quantity of zinc. 

The zinc which they make use of for the 
zincing, ought to be as pure as possible ; a very 
small proportion of wrought or cast iron in it, 
will render it unfit for the galvanic zincing; 
they can see if it is pure or not, by breaking a 
piece of it, that has not been flattened or rolled ; 
the facets of pure zinc, whether they are great 
or small, have an even and brilliant surface; if the 
zinc is again broken, the contrary is the case, 
with zinc which contains iron, it has always the 
facets rough, and as much more uneven and 
rough, as the zinc contains more iron. 



MISCELLANEOUS MATTER. 



Cleansing of the Galvanised ArtcUes. 

Likewise, as I have before said, the articles 
that come out of the melted zinc stained by the 
muriatic salt burnt, composed principally of the 
chlorure of iron and zinc ; to cleanse them of 
this salt, they spread on the articles some moist- 
ened sand, and they scrub them with brushes or 
pieces of cork; the cleansing is done more easi- 
ly if in the place of pure water to dilute the sand, 
they make use of water slightly acidulated with 
sulphuric acid. After this cleansing they wash 
them several times over and immediately; and 



after the washing, they dry the articles by 
ing them through saw-dust or bran; before 
making use of the saw-dust or bran, it is neces- 
sary to sift them, to cleanse the saw-dust, &c, 
from the earthy impurities, which would other- 
wise attach themselves to the articles, and soil 
them. 

END 

of the Second Series of Instructions : see now, 
the miscellaneous matter, which is, some part of 
it, of a great importance. 



MISCELLANEOUS MATTER. 



Galvanic Paint. 

This new preserving process, is based on the 
same principal: 

It is always by the galvanic effect of the zinc, 
when it comes in contact with the Iron, that this 
last metal is preserved from the Rust; but the 
manner of applying the zinc on the Iron is very 
different from the various processes I have de- 
scribed already: see in a few words, the manner 
of making the galvanic paint. 

They take the zinc reduced to a very fine 
powder, by the means that I am going to de- 
scribe or any other; and they dilute it with the 
oils, and other substances, usually employed for 
paints or varnishes: 

They may likewise put in the galvanic paint, 
all the various substances they employ to form 
the divers colours : 

The means that I use to pulverise the zinc, is 
very simple ; it consists in forming an amalga- 
mation of mercury, and of zinc, and when the 
mixture has become cold ; they pound it in a 
mortar: they can employ the same means to 
reduce in powder Lead, Tin, Copper and other 
metals : This mixture being reduced in powder, 
they heat it to evaporate the mercury : they 
ought during this operation to stir up the mix- 
ture, and to take care, not to heat it too much, 
for without these precautious it would become 
melted ; they would be able to operate the 
evaporation of the mercury in an Iron cylinder 
furnished in the inside with points, or provided 
with an agitator; they are to place this cylinder 
on the fire, and they will make it turn on its 
axletree, if they wish to save the mercury, that 
which is very important, when they make the 
paint on a ltrge scale ; they will make the 
cylinder communicate by one of its axeltrees 
with a reservoir of water, into which the mercury 
will pass, and become condensed : they would 
be able to dispen-e themselves of the trouble of 
evaporating the mercury, but in that case, the 
paint would cost more, without being any 
batter: 



One thing that I consider very important, is, 
to hinder the contact of the external air with 
the mixture during the evaporation of the 
mercury; in taking this precaution, the zinc 
powder w T ill have better retained its metallic 
colour, for it will not be tarnished with the 
oxygen. 

The galvanic paint can be employed on 
Copper, and other metals, they may likewise 
use the zinc powder alone, to contain polished 
metals that they wish to preserve. 



Galvanic Paint. 

This paint is made by mixing zinc, reduced 
into a very fine powder, with varnish or com- 
mon paint: now, it is a very important con- 
sideration to employ those means, that are the 
most simple and economical to reduce the zinc 
into powder: After a great number of experi- 
ments and trials, I have found a method simple 
and economical to reduce the zinc into pow r der: 
this method consists in forming a mixture of 
Iron and zinc: they put about ten parts of zinc 
for one of Iron ; this mixture after that it has 
become cold is extremely friable, and it will fall 
in powder of itself: they obtain the zinc powder 
finer still, in continually stirring the mixture 
during the time it takes to become cold, or in 
pounding it in a mortar that has been heated. 

The zinc powder mixed with wax or other 
substances can be employed to rub over arms, 
or other polished Iron articles, in order to pre- 
serve them from the rust, without materially 
diminishing their metalic brilliancy : I will men- 
tion here, in terminating, a fact foreign to the 
subject, but which is not perhaps without interest 
to science. 

I have observed that the mixture of Iron and 
zinc enjoys a curious property, which is contrary 
to the nearly general law of the constitution of 
subdued bodies: at a decrease of temperature, 
this mixture on the contrary, becomes consider- 
ably dilated in becoming cold, and breaks the 
vessel in which they have left it to become cold. 



MISCELLANEOUS MATTER. 



23 



The art or secret to make the paint red, red 
brown, green, and black: is as follows: take of 
cast Iron a quantity, and sprinkle it all over with 
water diluted with an equal quantity of muriatic 
acid: the sprinkling is to be continued from 
time to time, taking care to stir the Iron well 
up ; it will require about four pints of this mix- 
ture for 100 lbs. of Iron, and to be sprinkled 
once a day for three or four days ; afterwards 
leave it for 5 or 6 days more, and it will become 
heated by being left, at the expiration of this 
time, it is to be put in the cruset, and when all 
the smoke has evaporated it is finished; it does 
not require to remain long in the cruset or other 
vessel to heat it ; to make it red, it will be soon 
done ; to make it a brown red, it will require a 
little longer time to be heated; and to make 
it black it requires a longer time still. " To 
make the green paint :" take an equal quantity of 
zinc, and of Iron Rust, or of Cast Iron rusted, 
but mind particularly the Iron Rust, or the Cast 
Iron rusted is not to be sprinkled with the acid 
and water ; only immediately before it is put 
into the cruset along with the zinc, then when 
it is cooked sufficiently and become cool, it is 
put into the mill and ground into a fine powder ; 
of course it is intended that before putting it in- 
to the mill, it will be necessary to break the 
lumps in a mortar. 

I have said in another part that to reduce the 
zinc into powder, it was necessary to mix with 
it, one tenth part of its weight of iron filings, 
but since that time, experience has taught me 
that the presence of Iron, answered not fully in 
giving a preserving influence to the paint, &?c. 
This result has induced me to increase much 
the proportion of the Iron in the mixture: I 
put now at the least as much Iron as Zinc, I have 
even made very good paint in using wrought or 
cast Iron alone, partly rusted, and reduced in 
powder by the following method ; which con- 
sist: to heat strongly in a Vessel or an Oven, 
the wrought or cast Iron, that it is partly rusted, 
and in continually stirring it up during the ope- 
ration of heating, to facilitate the mixture of the 
metals, one with another, and to soften, and to 
rust the Iron: if they wish to employ the Iron 
alone, it is well to water it, with water that has 
been acidulated with the muriatic acid, before 
putting it on the fire : 

Experience has learnt me that the polishing 
(by means of a brush, and the burnishing, are 
the best and perhaps the only way of polishing) 
that is applicable to a zincing, for the reason 
that this method following regularly the surface 
of the zincing, without completely rubbing it oft' 
in places, as they would be liable to do with any 
other method, besides all that, this machine will 
cause the pieces of cork to pass four times more 
over the sheets of Iron. 



alkaline dissolutions to preserve iron articles, 
that it is not convenient to galvanise immediate- 
ly after the cleansing of the outer coat. 

I will just notice in this place that they can 
make a galvanic covering not only with Zinc, 
but likewise in mixing with this metal, different 
other metals, such as Tin, Lead, Bismuth, 
Mercury, Copper, &c. 



The method of heating the Vessels or Crusets, 
that appears to me the most suitable, consists to 
place around the Crusets, and in contact with 
them, coke or charcoal. 

The cylinder of the roller to prepare the gal- 
vanised sheets of Iron ought to be rough. 

They can employ Lime-water or any other 



The screws, and other parts of Iron articles 
that they wish not to be covered with the gal- 
vanic zincing, they cover these parts with a 
coat of clay, or if there are holes, they stop them 
up with wood, previous to their being put in the 
acid ; they can avoid on those parts of Machines, 
where it is not necessary to be prepared, the 
action of the acid, in covering them with Tallow 
or Wax; if they wish to give to the galvanised 
articles a particular grey colour, which is differ- 
ent to that of zinc ; they galvanise them in zinc, 
that is heated until it becomes red hot ; or after 
having covered them with zinc not altogether 
red hot, they will heat them red hot in a reflect- 
ing stove ; they can produce an oxyde very 
solid and durable by the galvanic covering, in 
moistening the pieces several limes over with 
a saturated dissolution of ammoniacal salt; the 
zinc powder which forms the base of the paint, 
can be made on a large scale in a reflecting 
stove, and they will also prepare in the same 
stove, the nails, and other small articles. 

To prepare very large sheets of Iron, without 
having very large crusets, they can make use of 
vessels of a half circular shape, they introduce 
the sheet by one side, and draw it out by the 
other side. 

The object of these few additional remarks, 
is the application of the galvanic process to mili- 
tary arms, and other articles in polished or filed 
Iron ; for these articles, the zincing, such as I 
ha\e described it previously, is not sufficient; 
the zincing ought to be done with the purest 
zinc ; and in a cruset of a rough kind of earth- 
en ware ; the crusets intended for articles of a 
large dimension, ought to be placed in other 
wrought or cast iron crusets, in order that they 
may be supported by these last ; they fill up 
with fine sand the space comprised between the 
earthen ware cruset and the one in iron; they 
cover the melted zinc with muriatic salt, in the 
manner I have before described; but to prevent 
the Salt from staining the articles in adhering to 
them, when they draw them out of the bath ; 
they mix with the muriatic salt, some earthy 
substances in powder or in pieces ; when the 
pieces are well covered by the zincing, they 
polish them ; they commence in the first place, 
by taking off with great care, all the uneyenness 
or roughness produced by the zincing, by 
means of files and scratching-knives, afterwards, 
they make use of pounded stone, of grit, or of 
sand paper ; after that they finish the polish as 
if it was on any other metal ; it is important not 
to make use of hard substances to prepare the 
zinced articles and to give the polish ; they 
ought to use Cork, Leather, a piece of Rag or 
similar things; as without taking this precaution, 
they would be apt to take off the zincing in cer- 
tain places. 



24 



MISCELLANEOUS MATTER. 



To cover Iron with a surface of Copper. 

They form a mixture of Copper and Zinc, in 
the proportion of one part of Copper for two of 
Zinc or thereabouts : This mixture ought to be 
white and very fragile ; the mixture being cold ; 
they pulverise it in a Mortar in mixing Borax 
with it ; the pieces of Iron, cast Iron, or Steel, 
that they wish to cover with Copper, being well 
cleansed of the Rust, or all other outer coat, 
they cover them all over with a greasy or vis- 
cous substance, and they sprinkle them with this 
mixture and Borax, afterwards they place them 
in charcoal powder, and they then heat them 
a sufficient time to evaporate the excess of zinc, 
they can easily perceive, that the operation is 
finished, by the little zinc vapour which escapes 
at the end of the operation: when they think 
proper to draw out the pieces of iron, they take 
them out with the charcoal which covers them, 
and they plunge them in water, with the char- 
coal still adhering to them, and whilst the pieces 
are yet red hot. 

After this operation, the Iron is perfectly 
covered with a coating or surface of Copper, 
of the which they can increase the brilliancy in 
dipping it in the sulphuric acid, into which they 
have put a little suet; they can thus polish and 
burnish this Copper, absolutely the same as if it 
was solid. 

CONCLUDING REMARKS. 

Certainly it is very important to know the 
temperature of the zinc Bath, and to know the 
temperature that is suitable for every article, 
either too hot or too cold, is bad. There is yet 
another important question to be strictly attended 
to. We can easily ascertain what is the strength 
of the acid Baths, but although that is a thing 
quite simple, it is much more important, to dis- 
cover the exact time, that the articles ought to 
remain in these Baths; to be cleansed of the 
outer surface or Oxyde ; and it is of an immense 
importance ; if these articles are of a delicate 
nature ; as for example steel stay Busks : every 

auarter of an hour, that the articles remain in 
le acid Bath, longer than is absolutely necessa- 
ry to cleanse off the outer surface ; is every 
quarter of an hour, given to the detriment of the 
quality of the articles : as the acids commence to 
corrode the substance of the metal, after the sur- 
face ; and although these things go unregarded 
in an establishment which is very badly ma- 
naged, like the one at Paris ; yet to a vigilant 
and careful manager everything of this kind will 
be strictly noticed, and even shades of difference 
strictly attended to, according to the Nature, the 
Strength, or Delicacy of the articles. 

It is quite easy to conceive that an article of 
great Bulk, and strongly made ; although left in 
the acid for too long a time, will naturally, resist 
better, than another article of a slighter make. 
The error is not so quickly discovered in the 
first; and in some cases is never found out, 
whilst in the latter the error is fatal : I will give 
an example that occurred to myself; in some 
Steel Stay Busks I had galvanised, the first two 
times they were properly done, and appeared to 



have preserved the temper of the Steel admira- 
bly, so I was encouraged to try a third quantity 
of the same article ; in the which I was wofully 
disappointed; for these Busks having been left 
through gross carelessness and ignorance for too 
long a time in the acid, they were absolutely 
good for nothing, entirely spoiled, the tempering 
quite gone. 

It is necessary to examine the articles from 
time to time, and likewise as much as possible 
to keep the acid Bath at the same strength, it 
would be well to test it eveiy morning before 
commencing, with the instrument for testing 
acids. 

Certainly, in a new discovery like this, there 
is reason in trying to make improvements, let 
each one who wishes to galvanise Iron make 
their own observations, their own experience, it 
is the only sure way never to be mistaken. 

To galvanise Iron is a thing very simple, and 
extremely easy to do, yet some will always do 
it better than others, this is the natural and legi- 
timate reward of skill and attention. 

As it is necessary that the articles should be 
washed in water after coming out of the Zinc 
Bath, to cleanse them from the blackish stains 
caused by the muriatic salt: it is likewise ne- 
cessary that this water should be warm ; and not 
promiscuously thrown into the cold water, 
whether it is Winter or Summer, as they do in 
Paris; every one's reason will tell them, that to 
throw an article into cold water in Winter, im- 
mediately it comes out of the nearly red hot 
Zinc, must harden it, must give a kind of 
tempering to the articles, must render them 
more brittle : To obviate this great inconve- 
nience ; the simple remedy is to heat the water 
to about 100 degrees of Farenheit: more par- 
ticularly in Winter. 

Then, there is another consideration: as the 
polishing and cleansing the articles from the 
stains caused by the muriatic salt, is not equally 
important for all articles ; and as those articles 
which do not go through this operation can be 
sold cheaper, without being any worse for use ; 
it would be more economical, to be content with 
simply washing those articles that do not require 
polishing; as for example, the sheets of iron 
destiued for roofing of buildings, &c. but to 
meet every taste, and obviate every objection, 
it would be easy to keep on hand, some which 
had been polished, and others which had been 
merely passed through the hot water, and to 
regulate the price accordingly. 

Thus, the manufacturer could offer to his 
customers the articles which look more beautiful, 
without being any better, at a price proportion- 
ly higher according to the labour bestowed upon 
them, and the other articles not so beautiful to 
look at, but equally good for use, at an iuferior 
price ; and each one coidd then please them- 
selves ; of course some articles must be properly 
and thoroughly cleansed from all the stains, to 
be able, to be offered in competition, with other 
articles, which have not had the advantage of 
being galvanised. 

GEORGE JOHNSON. 

Pari*, 29th July, 1841. 



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